Today is Memorial Day in the United States, a holiday to honor those who have died in the nation’s wars.

Visitors paying their respects at the Tomb of the Unknowns, Arlington National Cemetery, Virginia. Credit: James B. Blair/Corbis

It predates, but shares a similar focus with, Veterans Day, which is commemorated on November 11, the anniversary of the armistice that ended World War I. As Britannica reports:

It originated during the American Civil War (1861–64) when citizens placed flowers on the graves of those who had been killed in battle. A number of places claimed to have been the birthplace of the holiday. Among them, Columbus, Mississippi, held a formal observance for both the Union and the Confederate dead in 1866. By congressional proclamation in 1966, Waterloo, New York, was cited as the birthplace, also in 1866, of the observance in the North. In 1868 John A. Logan, the commander in chief of the Grand Army of the Republic, an organization of Union veterans, promoted a national holiday on May 30 “for the purpose of strewing with flowers or otherwise decorating the graves of comrades who died in defense of their country during the late rebellion.”

Similar holidays exist in countries around the world. Remembrance Sunday, held on the second Sunday in November, honors Britain’s war dead.

War veterans marching past the Cenotaph monument in London during a Remembrance Sunday service, 2006. Credit: Scott Barbour/Getty Images

ANZAC Day is marked on April 25 in Australia and New Zealand to commemorate the ill-fated Gallipoli Campaign landings during World War I. It has since come to honor all those who have died in Australia and New Zealand’s wars. As many of these memorial days have their origins in “the war to end all wars,” it is important to reflect on the 65 million men and women who served in that conflict—just one of whom survives today. Britannica’s Year in Review profiles 110-year-old Florence Patterson Green and the other Revered Last Veterans of World War I.